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Electron Beam Lithography for Vapor-Phase Deposition of Organosilanes
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- Author / Creator
- Fetterly, Christopher
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Self-assembly of functional groups on metal and metal oxide surfaces has been a foundation technology in micro- and nanofabrication. Confinement of reactive groups to a single molecular layer on a surface has been a rich field of scientific advancement, particularly with alkanethiolates on gold and silanes on silicon oxide. The ability to design interfaces that self-organize in the nanoscale regime for interesting macroscale applications has lead to advancements in fields such as genetics, energy storage, and textiles. Precise positioning of self-assembled monolayers in discrete regions on a surface allows for addressibility of a surface when the locations of reactivity are known. As feature sizes shrink towards the sub-10 nm regime, the density of functional elements increases on a surface, resulting in increased information density and higher throughput devices. Electron beam lithography (EBL) has been a longstanding tool used in the semiconductor industry to define nanoscale features on a surface. Unlike photolithography, EBL is not limited by the diffraction limit of light; EBL permits the design of arbitrary pattern geometries and at high resolution. Surfaces designed with EBL can be used to guide self-assembly, or to tailor pre-assembled surface chemistries. The result is a functional nanoscale pattern, with diverse application potential. This thesis is based on vapor-phase deposition of organosilanes. Using EBL to pattern a polymeric resist as a template, the system can be used to guide the deposition of organosilanes to discrete locations on a silicon oxide surface, confining reactive functional groups to defined nanoscale dimensions. Three different aspects of the method were investigated, which guided the arrangement of the thesis. The first was the use of the method to precisely position gold nanoparticles on a silicon surface, which was achieved by guiding the deposition of positively charged amine groups, which could bind negatively charged citrate-capped gold nanoparticles. The second aspect was the first report of EBL-defined condensation features with 3D morphology when depositing 3-aminopropyltrimethoxysilane. These structures were explored, with special attention to using these features as a spacer deposition process analogous to approaches used in semiconductor manufacturing. And finally, two lithographic approaches were compared for the construction of a fluorescent nanoarray. The thesis concludes with directions for optimization of each of these three aspects of EBL-guided vapor-phase deposition of organosilanes, and describes preliminary work to guide future efforts. The nanoparticle work may couple to existing research group directions in plasmonics. The 3D reactive amine features could be applied to established work in density doubling techniques, or directed self-assembly approaches. Lastly, the fluorescent nanoarray could be optimized to improve its application in superresolution
microscopy techniques. -
- Graduation date
- Fall 2018
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- Type of Item
- Thesis
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- Degree
- Doctor of Philosophy
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- License
- Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.